Purpose: The project will implement a range of activities to significantly improve the condition and vitality of reedbeds, particularly in areas with open-water pools (patches of deep water). These areas are the main breeding habitats of the Ferruginous Duck and Red-necked Grebe, as well as other waterbirds and reedbed bird species.
Monitoring of the breeding populations of reedbed birds will be carried out over the five project years. We will map the breeding habitats of reedbed birds and monitor the breeding-season activity of the Ferruginous Duck and Red-necked Grebe.
Implementation: Under the LIFE TRŠCA project, we worked with a KPI expert to update the project's key performance indicators (KPIs), enabling more effective monitoring of progress and achievement of the established objectives.
To better assess the impact of project activities, we began monitoring habitats, species and other indicators one year earlier than originally planned. This extended the monitoring period and improved the evidence base for evaluating the project's impacts. Particularly valuable data were collected in 2024, when prolonged flooding prevented mowing across many areas and created conditions similar to those that the project aims to establish in the long term through habitat management measures.
Before monitoring began, project partners jointly developed harmonised methods for surveys and field monitoring. All project partners involved in technical monitoring coordinate their work, regularly analyse the data collected and use the findings to adapt project activities and assess their effectiveness.
Purpose: To assess the impact of changes in land management on birds breeding in reedbeds, DOPPS will map their breeding areas. Approximately 300 ha of reedbeds will be surveyed, with 150 ha mapped every other project year. DOPPS will provide the equipment required for fieldwork, while NRP will purchase a canoe to facilitate access to less accessible areas. DOPPS will develop the methodology, conduct the surveys, process the data and prepare annual reports on the status of bird populations. In the final project year, a final report will be prepared, including an analysis of changes and an assessment of the project's impact.
Status: Task is in progress
Under the LIFE TRŠCA project, we are conducting extensive monitoring of reedbed birds and their habitats at Lake Cerknica. We established a monitoring system that allows the results to be compared with previous surveys conducted under the LIFE Stržen project.
The monitoring programme comprises eight transects with a total length of almost 24 km and 229 survey sections, making it one of the most extensive reedbed bird monitoring programmes at Lake Cerknica. Surveys are conducted several times during the breeding season, and the methodology has been further refined to include the precise recording of the locations of observed birds.
The data collected provide an important baseline for assessing the effects of habitat management, biomass removal, land purchases and other nature conservation measures implemented under the project.
In addition to bird monitoring, we also conduct habitat surveys, recording vegetation condition, habitat structure and land management practices. Joint analysis of habitat and ornithological data will improve our understanding of how management measures affect habitat quality and bird populations.
The results obtained to date provide a valuable basis for the long-term assessment of the LIFE TRŠCA project's impact on the conservation of reedbed habitats and the species that depend on them.
Results:
Purpose: Over five breeding seasons, DOPPS and NRP will conduct detailed monitoring of the Ferruginous Duck and Red-necked Grebe at Lake Cerknica. Four methods will be used: observations from viewing points along the western shore of the lake, surveys by canoe, camera traps deployed at open-water areas within the reedbeds, and drone surveys to locate nests. DOPPS and NRP will prepare annual reports on the status of the target species. In the final project year, an analysis of population changes and an assessment of the project's impact will be carried out.
Status: Task is in progress
Under the LIFE TRŠCA project, we are monitoring the status of both target species, the Ferruginous Duck (Aythya nyroca) and the Red-necked Grebe (Podiceps grisegena), and assessing the effects of conservation measures on their populations and habitats.
The monitoring combines several observation methods, including surveys from fixed observation points, boat-based surveys, camera monitoring and drone surveys. We purchased the necessary field equipment, established monitoring methodologies and trained staff in the use of modern data collection tools.
Regular surveys of the target species were carried out in 2025 and 2026. In addition to systematic observations, the analyses also incorporated records from other observers collected through ornithological databases. A dedicated expert report on the status of the target species was also prepared, providing an important baseline for assessing the effects of project activities in the coming years.
The monitoring revealed a high diversity of breeding bird species at Lake Cerknica. In both monitoring seasons, more than 1,000 breeding pairs belonging to approximately 30 species associated with reedbeds, wetlands and other aquatic habitats were recorded.
Although breeding by the target species had not yet been conclusively confirmed at the time of reporting, observations confirmed the presence of both species in the project area. The Ferruginous Duck was observed at several locations during the breeding season, and its population was estimated at up to six breeding pairs. The Red-necked Grebe was recorded during drone monitoring, confirming the importance of the area for this rare and threatened species.
Results:
The activities implemented under the project will significantly improve the vitality of marsh vegetation. Monitoring of the project's impact on marsh vegetation and its management will be carried out over the five project years. The monitoring will assess both the project's impact on reedbed vitality and changes in land management and habitat condition.
Purpose: To assess the impact of different management practices on reedbed vitality, the Biotechnical Faculty of the University of Ljubljana (UL BF) will conduct field-based and remote monitoring of reedbeds at Lake Cerknica over the five project years. The monitoring will cover six different reedbed types, classified according to management practices (annual mowing, occasional mowing and no mowing) and hydrological conditions. NRP will provide the multispectral satellite imagery required for this task. UL BF will prepare an annual report on reedbed vitality and, in the final project year, a final report analysing the effects of different management practices and hydrological conditions on reedbed vitality.
Status: Task is in progress
Under the LIFE TRŠCA project, we are monitoring marsh vegetation and reedbeds at Lake Cerknica to improve our understanding of how habitat management affects their quality and long-term conservation status. Monitoring is carried out at permanent sampling plots along survey transects and in areas covered by project measures.
In 2024, 2025 and 2026, we regularly monitored plant communities, reedbed vitality, biomass quantities and habitat changes. In addition to field surveys, we use satellite imagery and drone footage to monitor the extent and condition of reedbeds across the entire lake area.
The analyses indicate significant differences in reedbed quality and vitality and confirm that intensive mowing has a substantial impact on their condition. Satellite analyses have also revealed a noticeable decline in reedbed area in recent years, further highlighting the need for measures to conserve and restore these habitats.
To date, monitoring has been carried out at 42 permanent sampling plots, providing an important baseline for assessing the future effects of project activities. The data will enable us to evaluate the effectiveness of measures aimed at improving habitats and conserving species associated with marsh vegetation.
Another important outcome is the compilation of an extensive review of historical data on reedbeds at Lake Cerknica and the publication of a scientific article on the factors affecting the growth of common reed. Together with the interim report on the condition of wetland habitats, these resources provide a key baseline for assessing the long-term impacts of the LIFE TRŠCA project.
Results:
Purpose: Over the five project years, NRP will monitor the impact of project activities on changes in land use and management, as well as on habitat condition at Lake Cerknica. Each year, NRP will purchase four high-resolution satellite images covering the entire lake area, together with drone imagery of key areas of vital reedbeds. An annual report on land use and habitat condition will be prepared. In the final project year, an analysis of changes and an assessment of the project's impact will also be completed.
Status: Task is in progress
Under the LIFE TRŠCA project, we are monitoring changes in land use in the area of intermittent Lake Cerknica. We use satellite imagery, spatial analyses and field surveys to map mown and unmown areas annually.
In cooperation with the Faculty of Civil and Geodetic Engineering, we have also developed an advanced method for the automated detection of mowing based on satellite imagery. This enables more accurate monitoring of changes in habitat management and comparisons of data over extended periods.
The analyses indicate a long-term increase in mowing intensity across the lake area. On average, almost half of the project area is mown each year. The monitoring results provide an important evidence base for developing new and improved agri-environmental measures aimed at better protecting wetland habitats and the species that depend on them.
An interim report on changes in land use has also been prepared, providing an important baseline for monitoring the effects of project activities in the coming years. Together with vegetation monitoring, these data provide a comprehensive overview of changes in landscape management and their relationship with habitat condition at Lake Cerknica.
Results:
The project will implement a range of activities that will gradually improve habitats for waterbirds and mitigate the adverse effects of various types of disturbance during the breeding and wintering seasons. Over time, this is expected to contribute to an increase in waterbird populations. We will monitor waterbirds and track the extent of disturbance using an online database.
Purpose: Over the five-year project period, waterbird populations will be regularly monitored in the area of intermittent Lake Cerknica through observations from predefined observation points. Surveys will be conducted every 10 days, amounting to 36 surveys per year. Floating waterbird nests will also be surveyed using a drone. An annual report will be prepared presenting the results, while the final project year will include an analysis of population changes and an assessment of the project's impact on waterbird populations, including data on visitor-related disturbance.
Status: Task is in progress
Under the LIFE TRŠCA project, we are conducting extensive waterbird monitoring at Lake Cerknica. We have established a standardised methodology and a data storage system that enable long-term population monitoring and comparisons of results between years.
Since the beginning of the project, we have conducted 95 waterbird surveys at 25 permanent observation points. The data collected have helped identify the most important areas used by waterbirds and confirmed the key role of reedbeds and the hydrological regime in determining their distribution. Comparisons with surveys conducted in previous decades indicate an increase in the number of individuals recorded for certain species.
Particular attention has also been given to monitoring floating nests. During the 2025 and 2026 breeding seasons, we conducted 54 surveys, collecting valuable data on breeding habitat selection and the influence of site management on breeding bird species.
The monitoring results confirm the high nature conservation value of Lake Cerknica for numerous waterbird species. Analyses have shown that well-preserved reedbeds combined with open-water areas are particularly important for breeding, while intensive mowing can significantly influence the selection of nesting sites.
The data collected provide an important basis for adapting management measures and assessing the impact of the LIFE TRŠCA project on waterbird population status in the coming years.
Results:
Purpose: Throughout the project, we will monitor undesirable visitor activities that cause disturbance to waterbirds. All project partner staff will record disturbance events during fieldwork, including park rangers and surveyors monitoring birds, vegetation, land use and the hydrological regime. Data will be collected in the field using a mobile application and entered into a GIS database to support land management. At least 200 records will be collected annually.
Status: Task is in progress
Under the LIFE TRŠCA project, project partners systematically monitor disturbance and other relevant events in the natural environment during fieldwork at Lake Cerknica. Data are recorded using the Terenska beležnica application, developed under the project, which has become an important tool for monitoring conditions in the field.
To date, approximately 1,450 field records have been entered into the database, including more than 860 records from the area of intermittent Lake Cerknica, the main focus of project activities. Several dozen field visits have also been recorded, providing a more detailed overview of activities in the area.
Analysis of the collected data has shown that the most common sources of disturbance include driving off designated routes, allowing dogs to roam without a leash, fishing from boats and other visitor activities. Approximately 300 potential disturbance events affecting waterbirds have been recorded across the lake area.
The data collected provide an important basis for planning visitor management measures and reducing disturbance in sensitive habitats. At the same time, the Terenska beležnica demonstrates its value as a modern tool for monitoring conditions in the natural environment, which can also be used by other nature conservation organisations and protected area managers.
Results:
The water level of intermittent Lake Cerknica is extremely variable and unpredictable. The extent of the lake and the length of time it remains at a given size have a significant impact on both vegetation and the size of waterbird populations, as well as their breeding success. The task will be coordinated entirely by the Karst Research Institute.
Purpose: Based on water-level data and a high-resolution digital elevation model, the Karst Research Institute (IZRK ZRC SAZU) will calculate the surface area and volume of Lake Cerknica at different water levels. Using the complete set of hydrological data (1954–2022), as well as data specifically for the last 10 years (2012–2022), the average duration of the lake phase will also be calculated for different parts of the Cerknica polje, enabling trends in the water regime to be identified. In addition, IZRK will prepare calculations and digital maps for the dry phase of the lake, when water remains only in the river channels and in the Rešeto retention basin.
Status: Task is in progress
As part of the LIFE TRŠCA project, IZRK has prepared extensive hydrological and spatial datasets to improve understanding of the flooding dynamics of the Cerknica polje. Based on long-term hydrological data, satellite imagery and a high-resolution digital elevation model, maps have been produced for 31 different water-level scenarios, illustrating the extent of inundation at different water levels.
These datasets provide the most detailed insight to date into changes in the water surface area of Lake Cerknica and constitute an important tool for habitat management planning, interpretation of monitoring results and the development of nature conservation measures.
The spatial data produced are already being actively used in various project activities, as they provide a better understanding of the relationships between the water regime, habitat condition and the occurrence of plant and animal species in the area of the intermittent lake.
Results:
Purpose: Due to the size of the area and the complexity of its water regime, IZRK ZRC SAZU, in cooperation with NRP, will monitor flooding and drying dynamics across the Cerknica polje. Data from existing hydrological stations operated by the Slovenian Environment Agency (ARSO) will be analysed alongside data from new monitoring points established at Zadnji kraj, Levišča and in the reedbed near the confluence of the Lipsenjščica and Stržen rivers. IZRK and NRP will assess actual conditions through field measurements using RTK GNSS, analysis of satellite imagery and a digital elevation model. The drying of smaller water bodies—which provide key habitats for the Ferruginous Duck (Aythya nyroca) and the Red-necked Grebe (Podiceps grisegena)—will also be monitored over five years.
Status: Task is in progress
As part of the LIFE TRŠCA project, monitoring of the water regime across the Cerknica polje has been strengthened, as water levels are one of the key factors affecting the condition of wetland habitats and waterbird populations. In 2024, a continuous water-level monitoring system was established at eight new locations, providing more detailed data on the flooding and drying of the lake.
The measurement results confirmed that water levels vary across different parts of the Cerknica polje, significantly affecting habitat availability for plant and animal species. The data improve understanding of hydrological processes and enable nature conservation measures to be planned more precisely.
In addition to field measurements, scientific and technical publications on the hydrological and climatic characteristics of the Cerknica polje have also been prepared. These provide an important scientific basis for the long-term management and conservation of this unique intermittent lake.
Water-level data, together with habitat and bird monitoring results, are used to comprehensively assess the impact of the water regime on the natural environment and to monitor the effects of measures implemented under the LIFE TRŠCA project.
Results:
The implementation of extensive nature conservation projects exceeds the financial capacity of the local community, therefore Notranjska Park regularly applies for projects with the possibility of co-financing by the European Union.
The implementation of large-scale conservation projects exceeds the financial capabilities of the local community, therefore Notranjska Park regularly applies for projects with the possibility of co-financing from the European Union.
